johnstcn · Jul 16, 2026 · Jul 2, 2026 · Jul 6, 2026 · Jul 6, 2026 · Jul 8, 2026
diff --git a/coderd/apidoc/docs.go b/coderd/apidoc/docs.go
diff --git a/coderd/apidoc/swagger.json b/coderd/apidoc/swagger.json
diff --git a/coderd/database/dbauthz/dbauthz.go b/coderd/database/dbauthz/dbauthz.go
@@ -697,7 +697,8 @@ var (
 					rbac.ResourceApiKey.Type:                      {policy.ActionDelete},
 					rbac.ResourceAibridgeInterception.Type:        {policy.ActionDelete},
 					rbac.ResourceWorkspaceBuildOrchestration.Type: {policy.ActionDelete},
-					// Chat auto-archive sets archived=true on inactive chats.
+					// Chat auto-archive sets archived=true on inactive chats; the
+					// search_tsv backfill also updates chat messages.
 					rbac.ResourceChat.Type: {policy.ActionRead, policy.ActionUpdate},
 					// Purge old boundary logs past the retention period.
 					rbac.ResourceBoundaryLog.Type: {policy.ActionDelete},
@@ -1752,6 +1753,13 @@ func (q *querier) AutoArchiveInactiveChats(ctx context.Context, arg database.Aut
 	return q.db.AutoArchiveInactiveChats(ctx, arg)
 }
 
+func (q *querier) BackfillChatMessagesSearchTsv(ctx context.Context, batchSize int32) (int64, error) {
+	if err := q.authorizeContext(ctx, policy.ActionUpdate, rbac.ResourceChat); err != nil {
+		return 0, err
+	}
+	return q.db.BackfillChatMessagesSearchTsv(ctx, batchSize)
+}
+
 func (q *querier) BackoffChatDiffStatus(ctx context.Context, arg database.BackoffChatDiffStatusParams) error {
 	// This is a system-level operation used by the gitsync
 	// background worker to reschedule failed refreshes. Same
@@ -1829,6 +1837,14 @@ func (q *querier) CalculateAIBridgeInterceptionsTelemetrySummary(ctx context.Con
 	return q.db.CalculateAIBridgeInterceptionsTelemetrySummary(ctx, arg)
 }
 
+func (q *querier) ChatSearchQueryIsEmpty(ctx context.Context, search string) (bool, error) {
+	// Pure function, no rows. Gates on chat read to match the listing caller.
+	if err := q.authorizeContext(ctx, policy.ActionRead, rbac.ResourceChat); err != nil {
+		return false, err
+	}
+	return q.db.ChatSearchQueryIsEmpty(ctx, search)
+}
+
 func (q *querier) ClaimPrebuiltWorkspace(ctx context.Context, arg database.ClaimPrebuiltWorkspaceParams) (database.ClaimPrebuiltWorkspaceRow, error) {
 	empty := database.ClaimPrebuiltWorkspaceRow{}
 

diff --git a/coderd/database/dbauthz/dbauthz_test.go b/coderd/database/dbauthz/dbauthz_test.go
@@ -1012,6 +1012,14 @@ func (s *MethodTestSuite) TestChats() {
 		dbm.EXPECT().DeleteOldChats(gomock.Any(), database.DeleteOldChatsParams{}).Return(int64(0), nil).AnyTimes()
 		check.Args(database.DeleteOldChatsParams{}).Asserts(rbac.ResourceSystem, policy.ActionDelete)
 	}))
+	s.Run("BackfillChatMessagesSearchTsv", s.Mocked(func(dbm *dbmock.MockStore, _ *gofakeit.Faker, check *expects) {
+		dbm.EXPECT().BackfillChatMessagesSearchTsv(gomock.Any(), int32(100)).Return(int64(0), nil).AnyTimes()
+		check.Args(int32(100)).Asserts(rbac.ResourceChat, policy.ActionUpdate)
+	}))
+	s.Run("ChatSearchQueryIsEmpty", s.Mocked(func(dbm *dbmock.MockStore, _ *gofakeit.Faker, check *expects) {
+		dbm.EXPECT().ChatSearchQueryIsEmpty(gomock.Any(), "!!!").Return(true, nil).AnyTimes()
+		check.Args("!!!").Asserts(rbac.ResourceChat, policy.ActionRead)
+	}))
 	s.Run("GetChatRetentionDays", s.Mocked(func(dbm *dbmock.MockStore, _ *gofakeit.Faker, check *expects) {
 		dbm.EXPECT().GetChatRetentionDays(gomock.Any()).Return(int32(30), nil).AnyTimes()
 		check.Args().Asserts()

diff --git a/coderd/database/dbmetrics/querymetrics.go b/coderd/database/dbmetrics/querymetrics.go
diff --git a/coderd/database/dbmock/dbmock.go b/coderd/database/dbmock/dbmock.go
diff --git a/coderd/database/dbpurge/dbpurge.go b/coderd/database/dbpurge/dbpurge.go
@@ -51,6 +51,11 @@ const (
 	// Chat debug run deletions can cascade into steps with large JSONB
 	// payloads, so they use the same conservative batch size.
 	chatDebugRunsBatchSize = 1000
+	// 10k rows take ~800ms; capping at 5 batches bounds per-tick
+	// transaction growth at a few seconds. Larger backlogs drain
+	// across ticks.
+	chatSearchBackfillBatchSize  = 10000
+	chatSearchBackfillMaxBatches = 5
 )
 
 type Option func(*instance)
@@ -61,6 +66,14 @@ func WithClock(clk quartz.Clock) Option {
 	return func(i *instance) { i.clk = clk }
 }
 
+// WithChatSearchBackfillLimits overrides backfill batch size and cap. For tests.
+func WithChatSearchBackfillLimits(batchSize int32, maxBatches int) Option {
+	return func(i *instance) {
+		i.chatSearchBackfillBatchSize = batchSize
+		i.chatSearchBackfillMaxBatches = maxBatches
+	}
+}
+
 // New creates a new periodically purging database instance.
 // Callers must Close the returned instance.
 func New(ctx context.Context, logger slog.Logger, db database.Store, vals *codersdk.DeploymentValues, reg prometheus.Registerer, opts ...Option) io.Closer {
@@ -87,14 +100,26 @@ func New(ctx context.Context, logger slog.Logger, db database.Store, vals *coder
 	}, []string{"record_type"})
 	reg.MustRegister(recordsPurged)
 
+	// Separate counter: the backfill updates rows, not purges them.
+	chatSearchRowsBackfilled := prometheus.NewCounter(prometheus.CounterOpts{
+		Namespace: "coderd",
+		Subsystem: "dbpurge",
+		Name:      "chat_search_rows_backfilled_total",
+		Help:      "Total number of chat message rows whose search_tsv was backfilled.",
+	})
+	reg.MustRegister(chatSearchRowsBackfilled)
+
 	inst := &instance{
-		cancel:            cancelFunc,
-		closed:            closed,
-		logger:            logger,
-		vals:              vals,
-		clk:               quartz.NewReal(),
-		iterationDuration: iterationDuration,
-		recordsPurged:     recordsPurged,
+		cancel:                       cancelFunc,
+		closed:                       closed,
+		logger:                       logger,
+		vals:                         vals,
+		clk:                          quartz.NewReal(),
+		iterationDuration:            iterationDuration,
+		recordsPurged:                recordsPurged,
+		chatSearchRowsBackfilled:     chatSearchRowsBackfilled,
+		chatSearchBackfillBatchSize:  chatSearchBackfillBatchSize,
+		chatSearchBackfillMaxBatches: chatSearchBackfillMaxBatches,
 	}
 	for _, opt := range opts {
 		opt(inst)
@@ -310,6 +335,21 @@ func (i *instance) purgeTick(ctx context.Context, db database.Store, start time.
 			}
 		}
 
+		// Safe to run incrementally: queue membership is per-row, content is
+		// immutable after insert, and soft-deleted rows leave the index
+		// automatically.
+		var backfilledChatSearchRows int64
+		for range i.chatSearchBackfillMaxBatches {
+			n, err := tx.BackfillChatMessagesSearchTsv(ctx, i.chatSearchBackfillBatchSize)
+			if err != nil {
+				return xerrors.Errorf("backfill chat_messages.search_tsv: %w", err)
+			}
+			backfilledChatSearchRows += n
+			if n < int64(i.chatSearchBackfillBatchSize) {
+				break
+			}
+		}
+
 		i.logger.Debug(ctx, "purged old database entries",
 			slog.F("workspace_agent_logs", purgedWorkspaceAgentLogs),
 			slog.F("expired_api_keys", expiredAPIKeys),
@@ -322,6 +362,7 @@ func (i *instance) purgeTick(ctx context.Context, db database.Store, start time.
 			slog.F("chats", purgedChats),
 			slog.F("chat_files", purgedChatFiles),
 			slog.F("chat_debug_runs", purgedChatDebugRuns),
+			slog.F("chat_search_rows_backfilled", backfilledChatSearchRows),
 			slog.F("duration", i.clk.Since(start)),
 		)
 
@@ -338,6 +379,9 @@ func (i *instance) purgeTick(ctx context.Context, db database.Store, start time.
 			i.recordsPurged.WithLabelValues("chat_debug_runs").Add(float64(purgedChatDebugRuns))
 			i.recordsPurged.WithLabelValues("chat_files").Add(float64(purgedChatFiles))
 		}
+		if i.chatSearchRowsBackfilled != nil {
+			i.chatSearchRowsBackfilled.Add(float64(backfilledChatSearchRows))
+		}
 
 		// chatConfigErr is returned after the tx, so do not record this
 		// iteration as successful when only the deferred config read failed.
@@ -362,13 +406,16 @@ func (i *instance) purgeTick(ctx context.Context, db database.Store, start time.
 }
 
 type instance struct {
-	cancel            context.CancelFunc
-	closed            chan struct{}
-	logger            slog.Logger
-	vals              *codersdk.DeploymentValues
-	clk               quartz.Clock
-	iterationDuration *prometheus.HistogramVec
-	recordsPurged     *prometheus.CounterVec
+	cancel                       context.CancelFunc
+	closed                       chan struct{}
+	logger                       slog.Logger
+	vals                         *codersdk.DeploymentValues
+	clk                          quartz.Clock
+	iterationDuration            *prometheus.HistogramVec
+	recordsPurged                *prometheus.CounterVec
+	chatSearchRowsBackfilled     prometheus.Counter
+	chatSearchBackfillBatchSize  int32
+	chatSearchBackfillMaxBatches int
 }
 
 func (i *instance) Close() error {